Counter-demonstrators set a police van on fire in Örebro, where Danish politician Rasmus Paludan, had gotten permission to hold a demonstration on Friday.

Lyssna: National Police Chief: "No ordinary counter-demonstrators"

Anders Thornberg, the national police chief, said on Monday that they'd seen violent riots before, but that the riots that took place in several Swedish cities over the long Easter weekend were something different.

Thornberg said that the police had strong suspicions that those who attacked police and rescue services were linked to criminal gangs.

Petra Stenkula, Malmö police chief, also responded to criticism against police forces for issuing permission for the...